A per-case reimbursement mechanism for providers of in-hospital medical care will be studied and evaluated in terms of observed effects upon average lengths-of-stay and associated costs per episode of hospitalization for selected medical diagnoses. It is believed that this payment mechanism may affect the system of incentives for physicians in such a way as to encourage generally shorter lengths of stay, thereby offering opportunities for significant overall health care cost reductions. Proposed research and evaluation objectives will be accomplished by: 1. Developing a data base of patient characteristics and length-of- stay statistics by diagnosis for a test population receiving in-hospital medical care in the per-case reimbursement environment; 2. Developing a parallel data base of patient characteristics and length-of-stay statistics for a cross-sectional control group similar in every way to the test population, except that physician payments are not to be made by the per-case method. 3. Developing similar data bases for historical reference groups (i.e., longitudinal controls) associated with both the experimental group and the cross-sectional group; 4. Using non- parametric tests to determine the significance of observed differences in pair-wise comparisons between the various experience groups; and using conventional descriptive statistics to express the magnitude of any significant differences observed in length of stay; 5. Assessing health care cost implications by using appropriate costing methods to translate length-of-stay differentials into cost differentials for cases studied under the program.